CODEX SEARCH is an engine to recover information related to “immigration law” topic, based on linguistic tools and knowledge. An engine or Retrieval Information System (SRI) is a software able to locate information within large documentary collections (not trivial environment) in electronic format. It has been detected, through a previous study that “immigration law” is a discursive area in which it is difficult to express clearly what a person wants to know, in terms of a formal query, which is a fundamental aim of the current retrieval systems. Therefore, in order to develop an efficient SRI appropriate to the indicated domain, it is not enough to use a IR traditional model, that is, comparing the terms of the question with those of the answer, basically because they do not express implications and because there must not necessarily be a one-to-one relationship. According to this, the suggested linguistic solution is based on including the specialist’s knowledge through integrating a store of cases into the system. The cases are examples of procedures applied by experts to the solution of problems that have happened in the reality even they have finished successfully or not. The results obtained in this first phase are very encouraging but it is necessary to continue the research in this field, in order to improve the output of the prototype that can be entered from &http://161.116.36.139/~codex/&.